Homebrew solder pot is too dangerous even for us

[rue_mohr] is building a hexapod robot, and that meant he needed to tin a whole bunch of ribbon cables with solder. Using a soldering iron for this task would take far too long, so he built a homebrew solder pot to tin all those wires quickly. While [rue] was able to get solder on all those wires quickly, we need to question his method – he used a halogen light and reflector to melt all that solder.

The build began with a recycled halogen light fixture. After taking apart the entire assembly, [rue] reassembled it into something resembling a solder pot; a concave reflector and halogen light bulb sit perfectly flat on the table, ready to accept pieces of solder.

After throwing the switch and putting a few bits of solder in the reflector, the solder pot surprisingly worked. [rue] was able to quickly tin his ribbon cables, and the halogen bulb and reflector didn’t break yet.

This is one of the least safe solder pots we’ve ever seen – the bulb could easily explode, and melted solder could come pouring out of the reflector at any time. [rue] is aware of the safety implications and make sure to wear a pair of goggles. If it works though, we really can’t complain.

Check out the video of [rue]’s solder pot (with an awesome temperature indicator light right in the middle of a pool of solder) in action after the break.

this is a great idea, I have a similar setup on my bench. Mine doesnt involve the molten solder to actually contact the glass of the bulb, but it is very close. I use a copper container mounted over a halogen bulb. It takes a little to heat up, but once it does, it holds it well. Its also really nice in the colder months, haha.

Yes, it may seem a bit dangerous, but I really don’t think it’s that bad. The most important thing is (like he mentions on his site) removing the solder before it solidifies, otherwise it’s very likely to crack the bulb through compression. As far as temperatures are concerned, halogen bulbs operate at envelope temperatures up to 500 degrees C, so 300 degrees (or whatever) molten solder shouldn’t be a problem.

Glass is good at withstanding very high temperatures… that’s not likely to cause glass to break. What will shatter glass is uneven temperatures or sudden temp shifts, under certain conditions even temps under 110F can cause that.

Me not think so. What could happen? The glass breaks. Ok, molten solder will flow down and trigger the circuit breaker. End of story. There might be some solder flowing across the table etc., but there will be no explosion or anything. Putting a copper container in between is certainly a good idea, especially since it will barely affect effectiveness. Nonetheless, copper is destroyed over time by solder as well! And one could also topple a regular solder bath.
Simplest solution for me is one of these $10 solderpots consisting of a 100W soldering iron with a little pot at the end. Works fine and not much solder involved.

As slick as this seems I have to wonder if it would have been easier (safer) to just put a cup/bowl made of copper/sheet metal on top of the light (much akin to a Creepy Crawlers oven)to melt the solder.

I would definitely worry about molten solder being flung from a cracking/exploding halogen light.

keep the surface area down as much as you can, this will mean you need less power, which in turn, means it will cook you less than it does the solder. (somewhere I have a 50W radios—- iron with so much metal on teh shaft it can barely melt solder, but man does it do a good job cooking your hand!)

I totally feel ya bro, I was working on a live CRT oscilloscope on my bed because my desk was too cluttered as well! This is why hackers are so hard to find… we don’t have enough space on our workbenches…

just ran out and took a look, the solder freezing in the lamp dosn’t seem to have broken it! go figure….
I REALLY like the idea of using a copper ‘bowl’ over the lamp, but I’d have thought you would lose too much heat off it? guess I’d batter try it.
I’ll do up an article on how to store gas in lightbulbs for y’all.
look a dat, they really are about $30 (plug $40s&h) on ebay…. meh, I wanted one now.

Doesn’t copper alloy with solder? If you file the iron coating off soldering iron tips they seem to erode really quickly. If you put a load of molten solder in a copper bowl wouldn’t the copper bowl dissolve over time?

Rue is defiantly the guy who wouldn’t think of using a small cup to melt the solder “in”
On that thought I have seen small copper lined measuring scoops (think baking) that might be an appropriate vessel.

You have no idea how powerful those lasers are, do you? Wicked is one of the worst brands of lasers. There is no way a laser from wicked could heat up and melt that much solder. A candle would more readily melt that solder.

Thermal shock shouldn’t be an issue, so long as bulb is mostly immersed in the solder (hot or cold). The only issue really would be how to ensure the leads of the bulb do not make contact with the liquid solder and short out.

I made a solder pot myself once, and it was easy and cheap: go to Wal-mart (or your local equivalent), buy a $10 flat-element hot plate and a $1 stainless steel condiment cup.
The hot plate is much larger than the condiment cup, so it wastes a bunch of heat and you have to be careful not to burn your hands on the hot plate. Be sure to use the minimum setting on the hot plate that will keep the solder molten. In my case, it was about 70% power.
If you melt down wire solder instead of solder bars (like i did), melt down what you need, turn it off and let it cool, and clean off all the flux that floated to the top before you do your actual tinning.

I am usually the first to jump on safety but his is not really a big deal here. Its not going to explode or implode. Its just a MR-16 and the cover glass is usually pretty thick. And the amount of solder is tiny. Its not like a deep pool like in normal solder pots.

Even if the cover glass shatters the lamps is still enclosed. with the leads in ceramic potting so it can’t even short out.

nice hack. I think the risk is overblown, and the greatest risk are ones associated with being around molten metal. I might have to give this one a go. I think the most important thing is a nice heavy well insulated base.

Respect.. to Rue. and to the MR16. Just done some tests to see how much hot gasses will be released on failure.

MR16 up to temperature. splashed with cold water (standard globes will pop.) … nothing. MR16 up to temperature dumped into bath of water while on… nothing. MR16 underwater, running, and mechanically broken. Yes hot gasses do escape, but only after many bashes. These buggers are tough, but if they fail some splashing is likely to occur. One thought.. I’m not sure how much was hot gasses and how much was steam (which will not be present in the solder pot).

+1 Bravo. This is Hack-A-Day, where I seem to be one of the few worried about casually flashing a multi-watt laser out the window, then the mob get their knickers in a knot about using a QI as a heat lamp? Really guyz! Try and get a clue.

If anything, the major risk with any solder pot is ingesting lead vapour. Murray has just demonstrated that most of the concerns expressed above are baseless. Go for it Rue.

I would question the editorial sense and point out the possible liability involved in publishing this brainless stunt. It sure looks cute until the first person gets electrocuted or hospitalized with third degree burns.

You could say that for any article that so much as mentions line-power, or etchant, or heights over 3 feet.I think the HaD readers are smart enough to not jump off a bridge because there is an article that talks about a neat experiment you can do after you have achived terminal velocity. You CAN’T idiot-proof the world, you just can’t, trying will just enable there to be bigger idiots. They say that seatbelts cause a lot of deaths, this is because of the fact that people put a seatbelt on and behave carelessly beleiving that the safety systems will protect them from whatever could go wrong. Darwin awards are for those people who went out cause they just didn’t get it…. ok rant finished, point? ALWAYS use your best judgement as to if something is safe to do -OR BE NEAR- before doing it. I do not belive (I was being cuatious) this article says, anywhere, to build it.